A Novel Nanocomposite Photocatalyst for Water Treatment

用于水处理的新型纳米复合光催化剂

• 批准号: 7151018
• 负责人: ANUNCIA GONZALEZ-MARTIN
• 金额: $ 56.58万
• 依托单位: LYNNTECH, INC.
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-15 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7151018
• 关键词: catalyst; microorganism toxicology; nanotechnology; nonbiomedical equipment; oxidation; photochemistry; technology /technique development; water sampling /testing; water treatment

DESCRIPTION (provided by applicant): The availability of safe drinking water is a substantial health concern. The introduction of water chlorination as a standard water treatment has resulted in a significant decrease in the number of waterborne diseases. However disinfection byproducts (DBPs) are formed by the reactions between chlorine and the natural organic matter (NOM) dissolved in water. Long-term exposure to DBPs may increase the risk of cancer and other adverse health effect. As a consequence, the U.S. Environmental Protection Agency (EPA) has implemented stringent limits for DBPs in drinking water. Although the use of alternative disinfectants have been proposed, they also produce their own toxic byproducts. And water plant approaches to reduce the amount of NOM in the source water prior to chlorination step are not technically sound due to the requirement of a new water treatment plant that is costly to construct and operate. Thus, new methods for elimination of DBPs in drinking water at the point-of-use (POU) are strongly needed. The objective of the Phase II proposal is to design, fabricate and test a new, small-scale photocatalytic oxidation system for POU water treatment. The aim is to provide a unique, low-cost consumer device designed to effectively eliminate DBPs and microorganisms at the location where water is consumed. The proposed system provides attractive benefits over other POU technologies because it adds nothing harmful to the water, does not require routine service, does not provide a harbor for microorganism growth, and water contaminants including DBPs and microorganisms are destroyed, not just transferred from water to solid phase, and therefore, it does not create a waste disposal problem. During the Phase I project, Lynntech developed and successfully tested bench scale photocatalytic systems capable of fast degradation of a variety of microorganisms and DBPs to well bellow EPA recommended levels. It overcame limitations of other photocatalytic system including deactivation by inorganic ions. The heart of Lynntech's water treatment is the use of effective photocatalyst nanoparticles immobilized on an active matrix. The photocatalyst material is integrated into an ingenious reactor design that minimizes mass transfer and allows for fast treatment times. During the Phase II, an optimized automated GEN I POU photocatalytic water treatment will be developed. We will test it for its reliability, repeatability, ease of use, manufacturability and ease of assembly while minimizing its cost. Its operation will be on-line, and user interaction will be limited to the replacement of the UV lamps after about 5,000 hours of use. GEN I POU system will be extensively tested with DBPs and microorganisms commonly found in tap water. The proposed system has a high potential for user acceptance and has immediate commercial applications in many areas where high quality water is needed. Key segments where the proposed technology can have an immediate impact include hospital, schools, pharmacies, cafeteria, commercial and residential buildings, etc. The availability of safe drinking water is a substantial health concern. The introduction of water chlorination as a standard water treatment has resulted in a significant decrease in the number of waterborne diseases, but disinfection byproducts (DBPs) are formed by the reactions between chlorine and the natural organic matter (NOM) dissolved in water, and long-term exposure to DBPs may increase the risk of cancer and other adverse health effect. The aim of this Phase II proposal is to provide a unique, low-cost, small-scale photocatalytic oxidation system for point-of-use water treatment device designed to effectively eliminate DBPs and microorganisms at the location where water is consumed.

说明(申请人提供)：安全饮用水的可获得性是一个重大的健康问题。采用水氯化作为标准的水处理方法，大大减少了水传播疾病的数量。然而，消毒副产物(DBPs)是由氯和溶解于水中的天然有机物(NOM)反应形成的。长期接触邻苯二酚可能会增加患癌症的风险和其他不利的健康影响。因此，美国环境保护署(EPA)对饮用水中的DBP实施了严格的限制。虽然已经提出了使用替代消毒剂的建议，但它们也会产生自己的有毒副产品。在氯化步骤之前减少水源水中NOM含量的自来水厂方法在技术上并不健全，因为需要建造和运营成本高昂的新水处理厂。因此，迫切需要消除饮用水中使用点(POU)中的DBPs的新方法。 第二阶段方案的目标是设计、制造和测试一种用于POU水处理的新型小规模光催化氧化系统。其目的是提供一种独特的、低成本的消费设备，旨在有效地消除用水地点的DBPs和微生物。与其他POU技术相比，拟议的系统提供了有吸引力的好处，因为它不会添加任何对水有害的东西，不需要常规服务，不会为微生物生长提供避风港，而且包括DBPs和微生物在内的水污染物被销毁，而不仅仅是从水转移到固相，因此，它不会造成废物处理问题。 在第一阶段项目中，Lynntech开发并成功测试了实验室规模的光催化系统，能够将各种微生物和DBPs快速降解到EPA建议的水平以下。它克服了其他光催化体系的局限性，包括无机离子的失活。Lynntech水处理的核心是使用固定在活性基质上的有效光催化剂纳米颗粒。光催化剂材料被集成到一个巧妙的反应器设计中，最大限度地减少了传质，并允许快速处理时间。在第二阶段，将开发一种优化的自动化第一代POU光催化水处理系统。我们将测试它的可靠性、重复性、易用性、可制造性和组装简易性，同时将其成本降至最低。它的操作将是在线的，用户交互将仅限于在使用约5000小时后更换紫外线灯。Gen I POU系统将用自来水中常见的DBPs和微生物进行广泛测试。 建议的系统具有很高的用户接受度，并在许多需要高质量水的地区立即得到商业应用。提议的技术可以立即产生影响的关键领域包括医院、学校、药店、自助餐厅、商业和住宅建筑等。 安全饮用水的可获得性是一个重大的健康问题。引入水氯化作为标准的水处理方法，大大减少了水源性疾病的数量，但消毒副产物(DBPs)是由氯与水中溶解的天然有机物(NOM)反应而形成的，长期暴露于DBPs可能会增加患癌症的风险和其他不良健康影响。这一第二阶段提案的目的是为使用点水处理装置提供一种独特的、低成本的小规模光催化氧化系统，旨在有效地消除水消耗地点的二氯苯酚和微生物。